Understanding Computer Accessibility Features, Networking, and Internet Security

Posted on Sep 3, 2024 in Computers

Computer Accessibility Features

StickyKeys is an accessibility feature to help computer users with physical disabilities, but it is also used by others as a means to reduce repetitive strain.

FilterKeys is a feature of Microsoft Windows. It is an accessibility function that tells the keyboard to ignore brief or repeated keystrokes, making typing easier for people with hand tremors.

ToggleKeys is also a feature of Microsoft Windows. It is an accessibility function that is designed for people who have vision impairment or cognitive disabilities. When ToggleKeys is turned on, the computer emits sound cues when the locking keys (Caps Lock, Num Lock, or Scroll Lock) are pressed. A high sound is emitted when the keys are switched on and a low sound is emitted when they are switched off.

SoundSentry is designed to help users with auditory impairments. SoundSentry generates visual warnings, such as a blinking title bar or a flashing border, whenever the computer generates a sound.

ShowSounds instructs applications that convey information by sound to also provide information visually, through text captions or informative icons.

High Contrast is an accessibility feature to assist people with vision impairment. You can change the size and color of fonts and the background for ease of viewing.

Cursor Options is also an accessibility feature that assists people with vision impairment by changing the blink rate and width of the cursor.

MouseKeys is an accessibility feature that assists people who have difficulty using a mouse. This option uses the keyboard (especially the numeric keypad) as a pointing device instead of a mouse.

SerialKeys is an accessibility feature that assists people that have difficulty using a keyboard or a mouse (or both). They can use special devices such as sip, puff, and breath switches to provide input to the computer through serial ports.

Computer Networks and the Internet

A computer network is a collection of computers and other hardware components interconnected by communication channels (cables or satellites) that allow sharing of resources and information. This section introduces you to the basic fundamental concepts of networking and the internet, and using different types of internet connections.

Types of Networks

  • Peer-to-Peer (P2P) Networks: In which all computers have an equal status. Generally, in such a network, each terminal has an equally competent CPU.
  • Client-Server Networks: In which certain computers have special dedicated tasks, providing services to other computers (in the network). The computer(s) which provide services are called servers and the ones that use these services are called clients.
  • Local Area Network (LAN): Connects computers and devices in a limited geographical area such as a home, school, computer laboratory, office building, or closely positioned group of buildings. Usually, local area networks offer very high speeds and are used for connecting computers and peripherals such as printers, scanners, etc.
  • Wide Area Network (WAN): Covers a broad area (i.e., any network that links across metropolitan, regional, or national boundaries). The internet is the most popular WAN and is used by businesses, governments, non-profit organizations, individual consumers, artists, entertainers, and many others.

The Internet and the World Wide Web

The Internet is a global system of interconnected computer networks that use the standard Internet Protocol Suite to serve billions of users worldwide. It is a network of networks that consists of millions of private, public, academic, business, and government networks.

The World Wide Web (WWW), commonly known as the Web, is a system of interlinked hypertext documents accessed via the internet. With a web browser, one can view web pages that may contain text, images, videos, and other multimedia, and navigate between them via hyperlinks. Information is stored on web servers. Web pages are retrieved by using a web browser such as Firefox on the local computer. A web browser is software used to view websites and acts as an interface between the user and the World Wide Web. A web server is a computer that stores websites and their related files for viewing on the internet.

Advantages of Networking

  • Data Sharing: One of the most important uses of networking is to allow the sharing of data. Users can send text files, spreadsheets, documents, presentations, audio files, video files, etc. to other users.
  • Hardware Sharing: Hardware components such as printers, scanners, etc. can also be shared. For example, instead of purchasing ten printers for each user, one printer can be purchased and shared among multiple users, thus saving cost.
  • Internet Access Sharing: You can purchase a single internet connection and share it among other computers in a network instead of purchasing multiple internet connections for each computer. This is very commonly found in internet cafes (browsing centers), schools, colleges, companies, etc.
  • Usage of network-based applications such as web browsers, email clients, chat applications, audio and video calling, etc. is another advantage.

Internet Connections

To use the internet, you need an internet connection. Internet connections are provided by internet service providers such as Bharat Sanchar Nigam Limited (BSNL), Airtel, MTS, Vodafone, Tata Docomo, etc.

An Internet Service Provider (ISP) is an organization that provides you with access to the internet via a dial-up (using a modem) or direct (hard-wired) or wireless connection.

Types of Internet Connections

  • Dial-up: Dial-up internet access is a form of internet access that uses the facilities of the Public Switched Telephone Network (PSTN) to establish a connection to an Internet Service Provider (ISP) via telephone lines using a device called a modem. Users dial a particular number provided by the ISP and gain access to the internet. Dial-up connections are extremely slow and in most cases, it is replaced by a high-speed connection such as DSL or cable modem.
  • DSL: Digital Subscriber Line (DSL) provides internet access by transmitting digital data over wires of a local telephone network. DSL service is delivered along with wired telephone service on the same telephone line. On the customer premises, a DSL filter removes the high-frequency interference, enabling simultaneous use of the telephone and data transmission. For using a DSL connection, you need a DSL modem and a subscription.
  • Cable Internet Access: Cable internet access is a form of broadband internet access that uses the cable television infrastructure. Cable internet access is provided through existing cable TV networks; this is similar to DSL that is provided over existing telephone lines.
  • 3G: 3G, short for 3rd Generation, is a set of standards used for mobile devices and mobile telecommunication services and networks. High-Speed Downlink Packet Access (HSDPA) is a 3G mobile telephony communications protocol that allows higher data transfer speeds and capacity. If support for 3G is available on your mobile phone, you can subscribe to the 3G connectivity with your ISP to get a high-speed internet connection on your phone.
  • WiMAX: WiMAX (Worldwide Interoperability for Microwave Access) is a wireless communications standard designed to provide mobile broadband connectivity across cities and countries through a variety of devices. WiMAX is a long-range system, covering many kilometers, and is typically used where DSL or cable internet access cannot be used; this could be difficulty in laying out cables for homes or offices located in remote locations but need access to the internet.
  • Wi-Fi: Wi-Fi is a popular technology that allows an electronic device such as computers or mobile phones to exchange data wirelessly over a network, including high-speed internet connections. Wi-Fi devices such as personal computers, smartphones, video game consoles, etc. can connect to a network resource such as the internet through a device called the Wireless Access Point (WAP). Wi-Fi is used where cables cannot be run (such as old buildings, outdoor areas) to provide network and internet access. Wi-Fi can also be used where users require mobile connectivity.

Data Transfer on the Internet

Data is transferred on the internet in the following way:

  1. The data is broken up into bits of same-sized pieces called packets.
  2. A header is added to each packet explaining where the data has come from, where it should end up, and where it fits in with the rest of the packets.
  3. Each packet is sent from computer to computer until it finds its destination. Each computer on the way decides where next to send the packet. All packets may not take the same route.
  4. At the destination, the packets are examined. If any packets are missing or damaged, a message is sent asking for them to be re-sent. This continues until all packets have been received intact.
  5. The packets are now reassembled into their original form. All this is done in seconds!

To access Wi-Fi, you need an access point with an active internet connection. Usually, when you subscribe to an internet connection, the ISP provides options to purchase or rent a Wi-Fi router that can act as both an internet connectivity device and an access point for Wi-Fi connectivity. Setting up a Wi-Fi network requires technical expertise; however, you can access the Wi-Fi network by connecting to an access point that is already set up for use.

Instant Messaging (IM)

Instant messaging (IM) is a form of communication over the internet that offers instantaneous transmission of text-based messages from sender to receiver.

Key features of instant messaging are as follows:

  • Text messages can be sent to one or more persons (similar to SMS)
  • Audio calling and conferencing
  • Video calling and conferencing
  • File transfers (not limited to documents, spreadsheets, audio files, video files, etc.)
  • Message history (save messages for future reference)

Application-based instant messaging software is downloaded and installed on the user’s computer. Some of the popular instant messaging software are:

  • Google Talk
  • Yahoo! Messenger
  • Skype
  • Windows Live Messenger
  • Rediff Bol, etc.

Web-based instant messaging software is accessed using browsers such as Internet Explorer, Mozilla Firefox, Google Chrome, etc. Some of the popular web-based instant messaging software are:

  • Meebo
  • Yahoo! Messenger for the Web
  • MSN Web Messenger
  • IMO, etc.

Blogs

A blog is a discussion-style site used by non-technical (and technical) users for creating personal web pages. Blogs are similar to an online personal diary and simple to use. You can use a blog to convey messages about events, announcements, news, reviews, etc. Blogs are usually managed using a web browser and this requires an active internet connection. You can also use offline blog software to create content first and later publish the content when an active internet connection is available.

If you do not have an active internet connection, you can create blogs using a blog application and publish the blog whenever internet connectivity is available. There are several free offline blog editors available that can be downloaded and installed on the local computer such as:

  • Qumana
  • Windows Live Writer
  • Blogdesk

Online Shopping

Online shopping is a form of electronic commerce where customers can buy or sell goods over the internet. Customers need to have an active internet connection for viewing goods or services offered by a seller; customers can pay online using a credit or debit card.

Internet Security

Internet security is a branch of computer security specifically related to the internet, often involving browser security but also network security. Its objective is to establish rules and measures to use against attacks over the internet. The internet represents an insecure channel for exchanging information leading to a high risk of intrusion or fraud, such as phishing. This section introduces you to internet security concepts and how to secure online and network transactions.

You can reduce the risks by using best practices such as using antivirus software, antispyware software, firewalls, strong passwords, etc. in addition to spreading awareness of the best practices.

Best Practices for Internet Security

  • Strong Passwords:
    • Keep the length of the password at least 12-14 characters if permitted.
    • Avoid keeping passwords based on repetition, dictionary words, letter or number sequences, usernames, relative or pet names, etc.
    • Include numbers and symbols in passwords if allowed.
    • Use capital and lower-case letters.
    • Avoid using the same password for multiple sites or purposes.
    • Avoid using something that the public or workmates know you strongly like or dislike.
    • Use random password generators if possible.
  • Data Backup: Always keep copies of personal data in additional media such as compact discs, pen drives, etc. This could be helpful in situations when there is a loss of data. Keep the data away from unauthorized users. Use encryption software (usually available within the operating system) to protect your data from unauthorized users. If encryption software is not available within the operating system, use third-party software.
  • Privacy:
    • Keeping your username and password private: Never save your username or password on computers that are used in shared environments such as internet cafes. Browsers may save your personal data on the local computer that can be used by another user using the same computer.
    • Registering with websites: Read the privacy statement or policy whenever you register with a website, the statement or policy will include information about how the website uses personal data.
    • Do not share personal information: Websites require you to fill out forms containing fields such as name, gender, age, email address, school, etc. Be cautious when filling out such forms; research and verify if it’s a trustworthy website. Your email address could be used by unauthorized users to send you fake or unwanted emails; think twice or thrice before providing information to any website and decide if it is really necessary.
  • Secure Transactions: If you are using online shopping or transactions, websites even store your credit card or online banking personal information such as your credit card number, account details, etc. This information can be tracked and used by unauthorized users often known as hackers to misuse this information. Again, ensure the website is legitimate and uses secure practices for performing and maintaining online transactions. Since information such as credit card details or personal information is sent over the network, it is always recommended to use only secure websites for such transactions. Verify if the website uses secure transactions; usually, it is indicated through a digital certificate represented as a golden lock in the web browser’s address bar.
  • Antivirus and Antispyware Software: Computers are prone to attacks from software known as malware that could harm your computer. Malware tracks browsing behavior or transmits personal data from your computer; programs such as keyloggers could be installed on your computer to track and transmit every key that is pressed on a keyboard (keystrokes) to unauthorized users. Antivirus and Antispyware programs also offer real-time protection monitoring your computer for any changes by malware software. Keep your Antivirus and Antispyware software always up to date, this can help in protecting your computer from recent threats.
  • Email Security: Do not immediately respond to emails from unknown users, it may be a fake mail trying to gather personal information such as your bank account details, home address, etc. Some emails could promise you jobs or announce lottery results which in turn could compromise the user. And in some cases, viruses or scripts that are dangerous could be attached to the mail; NEVER open the attachment from an unknown source.
  • Browser Security: Clear browser cookies frequently, cookies are programs that are created on your local computer when you visit websites. Though cookies are meant for storing data based on your activity performed during your earlier visit such as logon details, details of a shopping cart, visited pages on a website, etc. they could also be tracked by unauthorized users and possibly gain access to your personal information.
  • Software Updates: Keep the operating system and software applications up to date; though operating systems and applications are designed, tested, and distributed, sometimes they may have security holes through which a hacker can take advantage; they may track and gather information or even damage the whole computer. In general, most vendors notify the users whenever a security hole is identified and an update is available to address that particular issue. You can also visit the respective vendor’s website to check if there are any updates available, download and keep your operating system and software applications up to date, free from security holes.
  • Firewalls: Firewalls could be software or hardware and can assist in keeping a computer and a network secure. Firewalls analyze the network traffic and determine if the traffic should be allowed or not. In most cases, operating systems such as Linux, Windows, or Mac include firewall software as a part of the operating system thus keeping the computer secure. In rare cases, you may need to configure your firewall for additional security.
  • Software Installation: Never install software from unknown sources as they might not be trustworthy; download only from well-known or reputed websites. Verify the source if it is legitimate by searching the internet or referring to comments from other users before downloading them; understand the nature and the purpose of the software before attempting to download and install them. Remove unwanted or unknown software applications; these might have gotten installed without your knowledge when you have visited some websites. Unwanted software could get installed as they might have been bundled along with necessary software. Some programs such as toolbars get installed usually through bundled software and are programmed to send personal data without your consent.